Java: Example - Drawing a Face - v4

// File: face/file2/Face.java 
// Author: Fred Swartz,  Date: July 1998 ... Oct 2004

import java.awt.*;
import javax.swing.*;

//////////////////////////////////////////////////////////////// class Face
class Face extends JPanel {
    //... Instance variables that define the "state" of the face.
    int mouthAngle   = 60;  // Number of degrees open the mouth is.
    int eyeDiameter  = 20;  // Size of the eye.
    int headDiameter = 200; // Size of the head.

    /** Constructor sets background color and initial size. */
    public Face() {
        this.setPreferredSize(new Dimension(300, 300));
        this.setBackground(Color.GRAY);
    }

    /** Override paintComponent to draw a face */
    public void paintComponent(Graphics g) {
        super.paintComponent(g);   // Required as first line.
        
        //... Get panel width and height, Compute center.
        int w = this.getWidth();
        int h = this.getHeight();
        int centerX = w / 2;  // x-coordinate of the center.
        int centerY = h / 2;  // y-coordinate of the center.
        
        //... Draw vertical lines in the background.
        g.setColor(Color.LIGHT_GRAY);
        for (int x=0; x < w; x += 10) {
            g.drawLine(x, 0, x, h);
        }

        //... Draw everything except the mouth in pink
        g.setColor(Color.PINK);
        g.fillArc(centerX - headDiameter / 2, centerY - headDiameter / 2
                 , headDiameter, headDiameter
                 , mouthAngle / 2, 360 - mouthAngle);

        //... Draw an eye
        g.setColor(Color.MAGENTA);
        g.fillOval(centerX + 20, centerY - 60, eyeDiameter, eyeDiameter);
    }
}